Liquid crystal composition and liquid crystal display device

ABSTRACT

To provide a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, and so forth. To provide an AM device having a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition contains a specific compound having a polymerizable group as a first component and a specific compound having a large negative dielectric anisotropy and a low minimum temperature as a second component, and may contain a specific compound having a small viscosity or a large maximum temperature as a third component, and a liquid crystal display device includes the composition.

TECHNICAL FIELD

The invention relates to a liquid crystal composition containing apolymerizable compound that is polymerized, for example, by light orheat. The invention also relates to a liquid crystal display device inwhich the liquid crystal composition is sealed between substrates, andthe polymerizable compound contained in the liquid crystal compositionis polymerized while adjusting a voltage applied to a liquid crystallayer to immobilize alignment of liquid crystals.

As the technical field, the invention relates to a liquid crystalcomposition mainly suitable for use in an active matrix (AM) device andso forth, and an AM device and so forth including the composition. Inparticular, the invention relates to a liquid crystal composition havinga negative dielectric anisotropy, and a device and so forth thatincluding the composition and having a mode such as an in-planeswitching (IPS) mode, a vertical alignment (VA) mode or a polymersustained alignment (PSA) mode. The VA mode includes a multi-domainvertical alignment (MVA) mode and a patterned vertical alignment (PVA)mode.

BACKGROUND ART

In a liquid crystal display device, a classification based on anoperating mode for liquid crystals includes a phase change (PC) mode, atwisted nematic (TN) mode, a super twisted nematic (STN) mode, anelectrically controlled birefringence (ECB) mode, an opticallycompensated bend (OCB) mode, an in-plane switching (IPS) mode, avertical alignment (VA) mode and a polymer sustained alignment (PSA)mode. A classification based on a driving mode in the device includes apassive matrix (PM) and an active matrix (AM). The PM is classified intostatic, multiplex and so forth, and the AM is classified into a thinfilm transistor (TFT), a metal insulator metal (MIM) and so forth. TheTFT is further classified into amorphous silicon and polycrystalsilicon. The latter is classified into a high temperature type and a lowtemperature type according to a production process. A classificationbased on a light source includes a reflective type utilizing naturallight, a transmissive type utilizing backlight and a transflective typeutilizing both the natural light and the backlight.

The devices include a liquid crystal composition having suitablecharacteristics. The liquid crystal composition has a nematic phase.General characteristics of the composition should be improved to obtainan AM device having good general characteristics. Table 1 belowsummarizes a relationship of the general characteristics between twoaspects. The general characteristics of the composition will be furtherexplained based on a commercially available AM device. A temperaturerange of the nematic phase relates to a temperature range in which thedevice can be used. A preferred maximum temperature of the nematic phaseis about 70° C. or higher and a preferred minimum temperature of thenematic phase is about −10° C. or lower. Viscosity of the compositionrelates to a response time in the device. A short response time ispreferred for displaying moving images on the device. Accordingly, asmall viscosity in the composition is preferred. A small viscosity at alow temperature is further preferred.

TABLE 1 General Characteristics of Composition and AM Device GeneralCharacteristics of General Characteristics of No. Composition AM Device1 Wide temperature range of Wide usable temperature a nematic phaserange 2 Small viscosity ¹⁾ Short response time 3 Suitable opticalanisotropy Large contrast ratio 4 Large positive or negative Lowthreshold voltage and dielectric anisotropy small electric powerconsumption Large contrast ratio 5 Large specific resistance Largevoltage holding ratio and large contrast ratio 6 High stability toultraviolet Long service life light and heat ¹⁾ A liquid crystalcomposition can be injected into a liquid crystal cell in a shorterperiod of time.

An optical anisotropy of the composition relates to a contrast ratio inthe device. A product (Δn×d) of the optical anisotropy (Δn) of thecomposition and a cell gap (d) in the device is designed so as tomaximize the contrast ratio. A suitable value of the product depends onthe type of the operating mode. The suitable value is in the range ofabout 0.30 micrometer to about 0.40 micrometer in a device having the VAmode or the PSA mode, and in the range of about 0.20 micrometer to about0.30 micrometer in a device having the IPS mode. In the above case, acomposition having a large optical anisotropy is preferred for a devicehaving a small cell gap. A large absolute value of dielectric anisotropyin the composition contributes to a low threshold voltage, a smallelectric power consumption and a large contrast ratio in the device.Accordingly, the large absolute value of dielectric anisotropy ispreferred. A large specific resistance in the composition contributes toa large voltage holding ratio and a large contrast ratio in the device.Accordingly, a composition having a large specific resistance at roomtemperature and also at a high temperature in an initial stage ispreferred. A composition having a large specific resistance at roomtemperature and also at a high temperature even after the device hasbeen used for a long period of time is preferred. Stability of thecomposition to ultraviolet light and heat relates to a service life ofthe liquid crystal display device. In the case where the stability ishigh, the device has a long service life. Such characteristics arepreferred for an AM device used in a liquid crystal projector, a liquidcrystal television and so forth.

A composition having a positive dielectric anisotropy is used for an AMdevice having the TN mode. On the other hand, a composition having anegative dielectric anisotropy is used for an AM device having the VAmode. A composition having a positive or negative dielectric anisotropyis used for an AM device having the IPS mode. A composition having apositive or negative dielectric anisotropy is used for an AM devicehaving the PSA mode. Examples of the liquid crystal composition havingthe negative dielectric anisotropy are disclosed in Patent literaturesNo. 1 to No. 6 as described below and so forth.

CITATION LIST Patent Literature

-   Patent literature No. 1: JP 2004-131704 A.-   Patent literature No. 2: JP 2009-102639 A.-   Patent literature No. 3: WO 2009/030318 A.-   Patent literature No. 4: WO 2009/030322 A.-   Patent literature No. 5: CN 101045866 A.-   Patent literature No. 6: JP 2009-132718 A.

A desirable AM device has characteristics such as a wide temperaturerange in which a device can be used, a short response time, a largecontrast ratio, a low threshold voltage, a large voltage holding ratioand a long service life. A shorter response time even by one millisecondis desirable. Thus, desirable characteristics of a composition include ahigh maximum temperature of a nematic phase, a low minimum temperatureof the nematic phase, a small viscosity, a suitable optical anisotropy,a large positive or negative dielectric anisotropy, a large specificresistance, a high stability to ultraviolet light and a high stabilityto heat.

Ina display having a PSA mode, a small amount (about 0.3% by weight,typically, less than about 1%, for example) of a polymerizable compound(RM) is added to a liquid crystal composition. After introduction into aliquid crystal display cell, only the polymerizable compound ispolymerized ordinarily under irradiation with ultraviolet light in astate in which a voltage is applied between electrodes to form a polymerstructure within the device. As the RM, a polymerizable mesogenic orliquid crystal compound is known to be particularly suitable as amonomer to be added to the liquid crystal composition.

SUMMARY OF INVENTION Technical Problem

In general, the polymerizable mesogenic or liquid crystal compounddescribed above has a high capability of aligning liquid crystalmolecules. On the contrary, the compound has a poor solubility in aliquid crystal composition, and cannot be added in a large amount. Inorder to prevent crystallization during transport or in a liquid crystaldisplay device, a polymerizable compound having a high solubility in theliquid crystal composition is desirable.

One of the aims of the invention is to provide a liquid crystalcomposition satisfying at least one of characteristics such as a highmaximum temperature of a nematic phase, a low minimum temperature of thenematic phase, a small viscosity, a suitable optical anisotropy, a largenegative dielectric anisotropy, a large specific resistance, a highstability to ultraviolet light and a high stability to heat. Another aimis to provide a liquid crystal composition having a suitable balanceregarding at least two of the characteristics. A further aim is toprovide a liquid crystal display device including such a composition. Astill further aim is to provide a composition having a suitable opticalanisotropy to be a small optical anisotropy or a large opticalanisotropy, a large negative dielectric anisotropy and a high stabilityto ultraviolet light, and so forth, and is to provide an AM devicehaving a short response time, a large voltage holding ratio, a largecontrast ratio, a long service life and so forth.

Solution to Problem

The invention concerns a liquid crystal composition containing at leastone compound selected from the group of compounds represented by formula(1) as a first component and at least one compound selected from thegroup of compounds represented by formula (2) as a second component, anda liquid crystal display device including the composition:

wherein R¹, R², R³ and R⁴ are independently hydrogen, hydroxy, alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkenyl having 2 to 12 carbons in which arbitraryhydrogen is replaced by fluorine, or a polymerizable group, and at leastone of R¹, R², R³ and R⁴ is a polymerizable group; R⁵ and R⁶ areindependently alkyl having 1 to 12 carbons, alkoxy having 1 to 12carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12carbons in which arbitrary hydrogen is replaced by fluorine; ring A andring C are independently 1,4-cyclohexylene, 1,4-phenylene in whicharbitrary hydrogen may be replaced by fluorine or chlorine, ortetrahydropyran-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹,Z², Z³ and Z⁴ are independently a single bond, oxygen, carbonyloxy,alkylene having 1 to 12 carbons or alkylene having 1 to 12 carbons inwhich arbitrary —CH₂— is replaced by —O—; Z⁵ and Z⁶ are independently asingle bond, ethylene, methyleneoxy or carbonyloxy; m is 1, 2 or 3; andn is 0 or 1, and a sum of m and n is 3 or less.

Advantageous Effects of Invention

An advantage of the invention is a high solubility of a polymerizablecompound in a liquid crystal composition. Another advantage of theinvention is a liquid crystal composition satisfying at least one ofcharacteristics such as a high maximum temperature of a nematic phase, alow minimum temperature of the nematic phase, a small viscosity, asuitable optical anisotropy, a large negative dielectric anisotropy, alarge specific resistance, a high stability to ultraviolet light and ahigh stability to heat. One aspect of the invention is a liquid crystalcomposition having a suitable balance regarding at least two of thecharacteristics. Another aspect is a liquid crystal display deviceincluding such a composition. A further aspect is a polymerizablecompound having a high solubility, a composition having a suitableoptical anisotropy, a large negative dielectric anisotropy, a highstability to ultraviolet light and so forth, and an AM device having ashort response time, a large voltage holding ratio, a large contrastratio, a long service life and so forth.

BEST MODE FOR CARRYING OUT THE INVENTION

Usage of terms herein is as described below. A liquid crystalcomposition or a liquid crystal display device of the invention may beoccasionally abbreviated as “composition” or “device,” respectively. Theliquid crystal display device is a generic term for a liquid crystaldisplay panel and a liquid crystal display module. “Liquid crystalcompound” means a compound having a liquid crystal phase such as anematic phase or a smectic phase, or a compound having no liquid crystalphase but being useful as a component of the composition. Such a usefulcompound has a six-membered ring such as 1,4-cyclohexylene and1,4-phenylene, and a rod-like molecular structure. An optically activecompound and a polymerizable compound may occasionally be added to thecomposition. Even in the case where the compounds are liquidcrystalline, the compounds are classified as an additive herein. Atleast one compound selected from the group of compounds represented byformula (1) may be occasionally abbreviated as “compound (1).” “Compound(1)” means one compound or two or more compounds represented by formula(1). A same rule applies to any other compound represented by any otherformula. A term “arbitrary” shows that not only positions but also thenumber can be freely selected, but does not include a case where thenumber is zero (0).

A maximum temperature of the nematic phase may be occasionallyabbreviated as “maximum temperature.” A minimum temperature of thenematic phase may be occasionally abbreviated as “minimum temperature.”An expression “having a large specific resistance” means that thecomposition has a large specific resistance at room temperature and alsoat a temperature close to the maximum temperature of the nematic phasein an initial stage, and that the composition has a large specificresistance at room temperature and also at a temperature close to themaximum temperature of the nematic phase even after the device has beenused for a long period of time. An expression “having a large voltageholding ratio” means that the device has a large voltage holding ratioat room temperature and also at a temperature close to the maximumtemperature of the nematic phase in an initial stage, and that thedevice has a large voltage holding ratio at room temperature and also ata temperature close to the maximum temperature of the nematic phase evenafter the device has been used for a long period of time. Whencharacteristics such as an optical anisotropy are explained, valuesobtained according to the measuring methods described in Examples willbe used. A first component includes one compound or two or morecompounds. “Ratio of the first component” is expressed in terms of aweight ratio (part by weight) of the first component based on 100 partsby weight of the liquid crystal composition excluding the firstcomponent “Ratio of a second component” is expressed in terms of weightpercent (% by weight) of the second component based on the weight of theliquid crystal composition excluding the first component. “Ratio of athird component” is expressed in a manner similar to “ratio of thesecond component.” A ratio of the additive mixed with the composition isexpressed in terms of weight percent (% by weight) or weight parts permillion (ppm) based on the total weight of the liquid crystalcomposition.

A symbol R⁵ is used for a plurality of compounds in chemical formulas ofcomponent compounds. A group to be selected by R⁵ may be identical ordifferent in two of arbitrary compounds among the plurality ofcompounds. In one case, for example, R⁵ of compound (2-1) is ethyl andR⁵ of compound (2-2) is ethyl. In another case, R⁵ of compound (2-1) isethyl and R⁵ of compound (2-2) is propyl. A same rule applies to asymbol R², R⁶ or the like.

The invention includes the items described below.

Item 1. A liquid crystal composition containing at least one compoundselected from the group of compounds represented by formula (1) as afirst component and at least one compound selected from the group ofcompounds represented by formula (2) as a second component:

wherein R¹, R², R³ and R⁴ are independently hydrogen, hydroxy, alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkenyl having 2 to 12 carbons in which arbitraryhydrogen is replaced by fluorine, or a polymerizable group, and at leastone of R¹, R², R³ and R⁴ is a polymerizable group; R⁵ and R⁶ areindependently alkyl having 1 to 12 carbons, alkoxy having 1 to 12carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12carbons in which arbitrary hydrogen is replaced by fluorine; ring A andring C are independently 1,4-cyclohexylene, 1,4-phenylene in whicharbitrary hydrogen may be replaced by fluorine or chlorine, ortetrahydropyran-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹,Z², Z³ and Z⁴ are independently a single bond, oxygen, carbonyloxy,alkylene having 1 to 12 carbons or alkylene having 1 to 12 carbons inwhich arbitrary —CH₂— is replaced by —O—; Z⁵ and Z⁶ are independently asingle bond, ethylene, methyleneoxy or carbonyloxy; m is 1, 2 or 3; andn is 0 or 1, and a sum of m and n is 3 or less.Item 2. The liquid crystal composition according to item. 1, wherein thefirst component is at least one compound selected from the group, ofcompounds represented by formula (1), and R¹, R², R³ and R⁴ areindependently hydrogen, hydroxy, alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2to 12 carbons in which arbitrary hydrogen is replaced by fluorine,acrylate, methacrylate, vinyloxy, propenyl ether, oxirane, oxetane orvinyl ketone, and at least one of R¹, R², R³ and R⁴ is acrylate,methacrylate, vinyloxy, propenyl ether, oxirane, oxetane or vinylketone.Item 3. The liquid crystal composition according to item 1 or 2, whereinthe first component is at least one compound selected from the group ofcompounds represented by formula (I-1) to formula (I-2):

wherein R² is hydrogen, hydroxy, alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2to 12 carbons in which arbitrary hydrogen is replaced by fluorine, or apolymerizable group.Item 4. The liquid crystal composition according to any one of items 1to 3, wherein the second component is at least one compound selectedfrom the group of compounds represented by formula (2-1) to formula(2-19):

wherein R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine.Item 5. The liquid crystal composition according to item 4, wherein thesecond component is at least one compound selected from the group ofcompounds represented by formula (2-1).Item 6. The liquid crystal composition according to item 4, wherein thesecond component is a mixture of at least one compound selected from thegroup of compounds represented by formula (2-1), and at least onecompound selected from the group of compounds represented by formula(2-6).Item 7. The liquid crystal composition according to item 4, wherein thesecond component is a mixture of at least one compound selected from thegroup of compounds represented by formula (2-1), and at least onecompound selected from the group of compounds represented by formula(2-13).Item 8. The liquid crystal composition according to item 4, wherein thesecond component is a mixture of at least one compound selected from thegroup of compounds represented by formula (2-4), and at least onecompound selected from the group of compounds represented by formula(2-8).Item 9. The liquid crystal composition according to any one of items 1to 8, wherein a ratio of the first component is in the range of 0.05part by weight to 10 parts by weight based on 100 parts by weight of theliquid crystal composition excluding the first component, and a ratio ofthe second component is in the range of 10% by weight to 90% by weightbased on the weight of the liquid crystal composition excluding thefirst component.Item 10. The liquid crystal composition according to any one of items 1to 9, further containing at least one compound selected from the groupof compounds represented by formula (3) as a third component:

wherein R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine; ring D and ring E are independently 1,4-cyclohexylene,1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or2,5-difluoro-1,4-phenylene; Z⁷ is independently a single bond, ethylene,methyleneoxy or carbonyloxy; and p is 1, 2 or 3.Item 11. The liquid crystal composition according to item 10, whereinthe third component is at least one compound selected from the group ofcompounds represented by formula (3-1) to formula (3-13):

wherein R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine.Item 12. The liquid crystal composition according to item 11, whereinthe third component is at least one compound selected from the group ofcompounds represented by formula (3-1).Item 13. The liquid crystal composition according to item 11, whereinthe third component is a mixture of at least one compound selected fromthe group of compounds represented by formula (3-1), and at least onecompound selected from the group of compounds represented by formula(3-5).Item 14. The liquid crystal composition according to item 11, whereinthe third component is a mixture of at least one compound selected fromthe group of compounds represented by formula (3-1), and at least onecompound selected from the group of compounds represented by formula(3-7).Item 15. The liquid crystal composition according to item 11, whereinthe third component is a mixture of at least one compound selected fromthe group of compounds represented by formula (3-1), at least onecompound selected from the group of compounds represented by formula(3-5), and at least one compound selected from the group of compoundsrepresented by formula (3-7).Item 16. The liquid crystal composition according to any one of items 10to 15, wherein a ratio of the third component is in the range of 10% byweight to 90% by weight based on the weight of the liquid crystalcomposition excluding the first component.Item 17. The liquid crystal composition according to any one of items 1to 16, further containing a polymerization initiator.Item 18. The liquid crystal composition according to any one of items 1to 17, further containing a polymerization inhibitor.Item 19. The liquid crystal composition according to any one of items 1to 18, wherein a maximum temperatures of a nematic phase is 70° C. orhigher, an optical anisotropy (25° C.) at a wavelength of 589 nanometersis 0.08 or more, and a dielectric anisotropy (25° C.) at a frequency of1 kHz is −2 or less.Item 20. A liquid crystal display device, constituted of two substrateshaving an electrode layer on at least one of the substrates, wherein theliquid crystal composition according to any one of items 1 to 19 isarranged between the two substrates.Item 21. The liquid crystal display device according to item 20, whereinan operating mode of the liquid crystal display device is a TN mode, aVA mode, an IPS mode or a PSA mode, and a driving mode of the liquidcrystal display device is an active matrix mode.Item 22. Use of the liquid crystal composition according to any one ofitems 1 to 19 in a liquid crystal display device.

The invention also includes the following items: (1) the composition,further containing the optically active compound; (2) the composition,further containing the additive such as an antioxidant, an ultravioletlight absorber or an antifoaming agent; (3) an AM device including thecomposition; (4) a device including the composition, and having a TN,ECB, OCB, IPS, VA or PSA mode; (5) a transmissive device including thecomposition; (6) use of the composition as the composition having thenematic phase; and (7) use of the composition as an optically activecomposition by adding the optically active compound thereto.

The composition of the invention will be explained in the followingorder. First, a constitution of the component compounds in thecomposition will be explained. Second, main characteristics of thecomponent compounds and main effects of the compounds on the compositionwill be explained. Third, a combination of components in thecomposition, a preferred ratio of the components and the basis thereofwill be explained. Fourth, a preferred embodiment of the componentcompounds will be explained. Fifth, specific examples of the componentcompounds will be shown. Sixth, an additive that may be mixed with thecomposition will be explained. Seventh, methods for synthesizing thecomponent compounds will be explained. Last, an application of thecomposition will be explained.

First, the constitution of the component compounds in the compositionwill be explained. The composition of the invention is classified intocomposition A and composition B. Composition A may further contain anyother liquid crystal compound, an additive, an impurity, or the like, inaddition to a compound selected from compound (1), compound (2) andcompound (3). “Any other liquid crystal compound” means a liquid crystalcompound different from compound (1), compound (2) and compound (3).Such a compound is mixed with the composition for the purpose of furtheradjusting the characteristics. Of any other liquid crystal compounds, aratio of a cyano compound is preferably as small as possible in view ofstability to heat or ultraviolet light. A further preferred ratio of thecyano compound is 0% by weight. The additive includes the opticallyactive compound, the antioxidant, the ultraviolet light absorber, a dye,the antifoaming agent, the polymerizable compound and the polymerizationinitiator. The impurity includes a compound mixed in a process such aspreparation of the component compounds. Even in the case where thecompound is liquid crystalline, the compound is classified as theimpurity herein.

Composition B consists essentially of compounds selected from compound(1), compound (2) and compound (3). A term “essentially” means that thecomposition may contain the additive and the impurity, but does notcontain any liquid crystal compound different from the compounds.Composition B has a smaller number of components than composition A has.Composition B is preferred to composition A in view of cost reduction.Composition A is preferred to composition B in view of possibility offurther adjusting physical properties by mixing any other liquid crystalcompound.

Second, the main characteristics of the component compounds and the maineffects of the compounds on the characteristics of the composition willbe explained. The main characteristics of the component compounds aresummarized in Table 2 on the basis of advantageous effects of theinvention. In Table 2, a symbol L stands for “large” or “high,” a symbolM stands for “medium,” and a symbol S stands for “small” or “low.” Thesymbols L, M and S represent a classification based on a qualitativecomparison among the component compounds, and 0 (zero) means “a value isclose to zero.”

TABLE 2 Characteristics of Compounds Compounds Compound (2) Compound (3)Maximum temperature S to L S to L Viscosity M to L S to M Opticalanisotropy M to L S to L Dielectric anisotropy M to L ¹⁾ 0 Specificresistance L L ¹⁾ A value of dielectric anisotropy is negative, and thesymbol shows magnitude of an absolute value.

Upon mixing the component compounds with the composition, the maineffects of the component compounds on the characteristics of thecomposition are as described below. Compound (2) increases the absolutevalue of dielectric anisotropy, and decreases the minimum temperature.Compound (3) decreases the viscosity, or increases the maximumtemperature.

Third, the combination of components in the composition, the preferredratio of the components and the basis thereof will be explained. Thecombination of the components in the composition includes a combinationof the first component and the second component, and a combination ofthe first component, the second component and the third component.

A preferred ratio of the first compound is about 0.05 part by weight ormore for achieving the effect thereof, and about 10 parts by weight orless for avoiding a poor display, based on 100 parts by weight of theliquid crystal composition excluding the first component. A furtherpreferred ratio is in the range of about 0.1 part by weight to about 2parts by weight.

A preferred ratio of the second component is about 10% by weight or morefor increasing the absolute value of dielectric anisotropy, and about90% by weight or less for decreasing the minimum temperature, based onthe liquid crystal composition excluding the first component. A furtherpreferred ratio is in the range of about 20% by weight to about 80% byweight. A particularly preferred ratio is in the range of about 30% byweight to about 70% by weight.

A preferred ratio of the third component is about 10% by weight or morefor decreasing the viscosity or increasing the maximum temperature, andabout 90% or less for increasing the absolute value of dielectricanisotropy, based on the liquid crystal composition excluding the firstcomponent. A further preferred ratio is in the range of about 20% byweight to about 80% by weight. A particularly preferred ratio is in therange of about 30% by weight to about 70% by weight.

Fourth, the preferred embodiment of the component compounds will beexplained. R¹, R², R³ and R⁴ are independently hydrogen, hydroxy, alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkenyl having 2 to 12 carbons in which arbitraryhydrogen is replaced by fluorine, or a polymerizable group, and at leastone of R¹, R², R³ and R⁴ is a polymerizable group. Preferred R¹, R², R³and R⁴ are hydrogen, hydroxy, acrylate or methacrylate for increasingphotoreactivity. R⁵, R⁶, R⁷ and R⁸ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, or alkenyl having 2 to 12 carbons in which arbitrary hydrogenis replaced by fluorine. Preferred R⁵ or R⁶ is alkyl having 1 to 12carbons for increasing the stability to ultraviolet light, and so forth,or increasing the stability to heat, and alkoxy having 1 to 12 carbonsfor increasing the absolute value of dielectric anisotropy. Preferred R⁷or R⁸ is alkyl having 1 to 12 carbons for increasing the stability toultraviolet light, or increasing the stability to heat, and alkenylhaving 2 to 12 carbons for decreasing the minimum temperature.

Preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptylor octyl. Further preferred alkyl is ethyl, propyl, butyl, pentyl orheptyl for decreasing the viscosity.

Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy or heptyloxy. Further preferred alkoxy is methoxy or ethoxy fordecreasing the viscosity.

Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl,2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl,1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. Furtherpreferred alkenyl is vinyl, 1-propenyl, 3-butenyl or 3-pentenyl fordecreasing the viscosity. A preferred configuration of —CH═CH— in thealkenyl depends on a position of a double bond. Trans is preferred inthe alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl,3-pentenyl and 3-hexenyl for decreasing the viscosity, for instance. Cis preferred in the alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl.In the alkenyl, straight-chain alkenyl is preferred to branched-chainalkenyl.

Preferred examples of alkenyl in which arbitrary hydrogen is replaced byfluorine include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl,4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl and6,6-difluoro-5-hexenyl. Further preferred examples include2,2-difluorovinyl and 4,4-difluoro-3-butenyl for decreasing theviscosity.

Ring A and ring C are independently 1,4-cyclohexylene, 1,4-phenylene inwhich arbitrary hydrogen may be replaced by fluorine or chlorine, ortetrahydropyran-2,5-diyl. Tetrahydropyran-2,5-diyl includes:

preferably,

Tetrahydropyran-2,5-diyl is left-right asymmetrical. However, as adefinition, the rings can be located not only in a direction defined butalso in a reversed left-right direction as described above. Thedefinition also applies to any other ring in which only one direction isdefined in a left-right asymmetrical ring.

Ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene,2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diylor 7,8-difluorochroman-2,6-diyl, and two of arbitrary ring A when m is 2or 3 may be identical or different. Preferred ring A or ring C is1,4-cyclohexylene for decreasing the viscosity. Preferred ring B is2,3-difluoro-1,4-phenylene for decreasing the viscosity and increasingthe absolute value of dielectric anisotropy. Ring D and ring E areindependently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenyleneor 3-fluoro-1,4-phenylene, and two of arbitrary ring D when p is 2 or 3may be identical or different. Preferred ring D or ring E is1,4-cyclohexylene for decreasing the viscosity, and 1,4-phenylene forincreasing the optical anisotropy. With regard to a configuration of1,4-cyclohexylene, trans is preferred to cis for increasing the maximumtemperature.

Z¹, Z², Z³ and Z⁴ are independently a single bond, oxygen, carbonyloxy,alkylene having 1 to 12 carbons, or alkylene having 1 to 12 carbons inwhich arbitrary —CH₂— is replaced by —O—. Preferred Z¹, Z², Z³ and Z⁴are a single bond for increasing the photoreactivity. Z⁵, Z⁶ and Z⁷ areindependently a single bond, ethylene, methyleneoxy or carbonyloxy, twoof arbitrary Z⁵ when m is 2 or 3 may be identical or different, and twoof arbitrary Z⁷ when p is 2 or 3 may be identical or different.Preferred Z⁵ or Z⁶ is a single bond for decreasing the viscosity, andmethyleneoxy for increasing the absolute value of dielectric anisotropy.Preferred Z⁷ is a single bond for decreasing the viscosity.

Then, m is 1, 2 or 3, n is 0 or 1, and a sum of m and n is 3 or less.Preferred m is 1 for decreasing the minimum temperature. Preferred n is0 for decreasing the viscosity. Then, p is 1, 2 or 3. Preferred p is 1for decreasing the viscosity, and 3 for increasing the maximumtemperature.

Fifth, the specific examples of the component compounds will be shown.In the preferred compounds described below, R⁹ is hydrogen, hydroxy,acrylate or methacrylate. R¹⁰ is straight-chain alkyl having 1 to 12carbons or straight-chain alkoxy having 1 to 12 carbons. R¹¹ and R¹² areindependently straight-chain alkyl having 1 to 12 carbons orstraight-chain alkenyl having 2 to 12 carbons.

Preferred compound (1) includes compound (1-1-1) and compound (1-2-1).Further preferred compound (1) includes compound (1-1-1). Preferredcompound (2) includes compound (2-1-1) to compound (2-19-1). Furtherpreferred compound (2) includes compound (2-1-1), compound (2-2-1),compound (2-4-1), compound (2-6-1), compound (2-8-1), compound (2-11-1)and compound (2-13-1). Particularly preferred compound (2) includescompound (2-1-1), compound (2-4-1), compound (2-6-1), compound (2-8-1)and compound (2-13-1). Preferred compound (3) includes compound (3-1-1)to compound (3-13-1). Further preferred compound (3) includes compound(3-1-1), compound (3-3-1), compound (3-5-1), compound (3-7-1) andcompound (3-9-1). Particularly preferred compound (3) includes compound(3-1-1), compound (3-5-1) and compound (3-7-1).

Sixth, the additive that may be mixed with the composition will beexplained. Such an additive includes the optically active compound, theantioxidant, the ultraviolet light absorber, the dye, the antifoamingagent, the polymerization initiator and the polymerization inhibitor.The optically active compound is mixed with the composition for thepurpose of inducing a helical structure in liquid crystals to give atwist angle. Examples of such a compound include compound (4-1) tocompound (4-4). A preferred ratio of the optically active compound isabout 5% by weight or less. A further preferred ratio is in the range ofabout 0.01% by weight to about 2% by weight.

The antioxidant is mixed with the composition for the purpose ofpreventing a decrease in the specific resistance caused by heating inair, or maintaining a large voltage holding ratio at room temperatureand also at a temperature close to the maximum temperature of thenematic phase after the device has been used for a long period of time.

Preferred examples of the antioxidant include compound (5) where is aninteger from 1 to 9. In compound (5), preferred s is 1, 3, 5, 7 or 9.Further preferred s is 1 or 7. Compound (5) where s is 1 is effective inpreventing a decrease in the specific resistance caused by heating inair because the compound (5) has a large volatility. Compound (5) wheres is 7 is effective in maintaining a large voltage holding ratio at roomtemperature and also at a temperature close to the maximum temperatureof the nematic phase after the device has been used for a long period oftime because the compound (5) has a small volatility. A preferred ratioof the antioxidant is about 50 ppm or more for achieving the effectthereof, and about 600 ppm or less for avoiding a decrease in themaximum temperature or avoiding an increase in the minimum temperature.A further preferred ratio is in the range of about 100 ppm to about 300ppm.

Preferred examples of the ultraviolet light absorber include abenzophenone derivative, a benzoate derivative and a triazolederivative. A light stabilizer such as an amine having steric hindranceis also preferred. A preferred ratio of the ultraviolet light absorberor the stabilizer is about 50 ppm or more for achieving the effectthereof, and about 10,000 ppm or less for avoiding a decrease in themaximum temperature or avoiding an increase in the minimum temperature.A further preferred ratio is in the range of about 100 ppm to about10,000 ppm.

A dichroic dye such as an azo dye or an anthraquinone dye is mixed withthe composition to be adapted for a device having a guest host (GH)mode. A preferred ratio of the dye is in the range of about 0.01% byweight to about 10% by weight.

The antifoaming agent such as dimethyl silicone oil or methyl phenylsilicone oil is mixed with the composition for preventing foamformation. A preferred ratio of the antifoaming agent is about 1 ppm ormore for achieving the effect thereof, and about 1,000 ppm or less foravoiding a poor display. A further preferred ratio is in the range ofabout 1 ppm to about 500 ppm.

The liquid crystal composition of the invention is suitable for use inthe device having the polymer sustained alignment (PSA) mode because thecomposition contains the polymerizable compound. The composition mayfurther contain a polymerizable compound other than compound (1).Preferred examples of the polymerizable compound include a compoundhaving a polymerizable group, such as an acrylate, a methacrylate, avinyl compound, a vinyloxy compound, a propenyl ether, an epoxy compound(oxirane, oxetane) and a vinyl ketone. Particularly preferred examplesinclude an acrylate derivative or a methacrylate derivative. A preferredratio of the polymerizable compound is about 0.05% by weight or more forachieving the effect thereof, and about 10% by weight or less foravoiding a poor display. A further preferred ratio is in the range ofabout 0.1% by weight to about 2% by weight. The polymerizable compoundis preferably polymerized by irradiation with ultraviolet light or thelike in the presence of a suitable initiator such as aphotopolymerization initiator. Suitable conditions for polymerization,suitable types of the initiator and suitable amounts thereof are knownto a person skilled in the art and are described in literatures. Forexample, Irgacure 651 (registered tradename; BASF), Irgacure 184(registered tradename; BASF) or Darocure 1173 (registered tradename;BASF), each being a photoinitiator, is suitable for radicalpolymerization. A preferred ratio of the photopolymerization initiatoris in the range of about 0.1% by weight to about 5% by weight, and afurther preferred ratio is in the range of about 1% by weight to about3% by weight, based on the polymerizable compound. The device may bemanufactured through a process of arranging the liquid crystalcomposition containing the polymerizable compound between two substratesin the liquid crystal display device and polymerizing the polymerizablecompound while applying a voltage between opposing electrode layers onthe substrates, or by arranging a liquid crystal composition containinga preliminarily polymerized compound between the two substrates in theliquid crystal display device.

Seventh, the methods for synthesizing the component compounds will beexplained. The compounds can be prepared by known methods. Examples ofsynthetic methods will be shown. Compound (1-1-1) is commerciallyavailable from Toagosei Co., Ltd. Compound (2-1-1) is prepared by themethod disclosed in JP 2000-053602A. Compound (3-1-1) and compound(3-5-1) are prepared by the method disclosed in JP S59-176221 A. Theantioxidant is commercially available. A compound represented by formula(5) where s is 1 is available from Sigma-Aldrich Corporation. Compound(5) where s is 7 and so forth are prepared according to the methoddescribed in U.S. Pat. No. 3,660,505 B.

Any compounds whose synthetic methods are not described above can beprepared according to the methods described in books such as OrganicSyntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley &Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press) and NewExperimental Chemistry Course (Shin Jikken Kagaku Koza in Japanese)(Maruzen Co., Ltd.). The composition is prepared according to publiclyknown methods using the thus obtained compounds. For example, thecomponent compounds are mixed and dissolved in each other by heating.

Last, the application of the composition will be explained. Most of thecompositions have a minimum temperature of about −10° C. or lower, amaximum temperature of about 70° C. or higher and an optical anisotropyin the range of about 0.07 to about 0.20. The device including thecomposition has a large voltage holding ratio. The composition issuitable for use in the AM device. The composition is particularlysuitable for use in a transmissive AM device. A composition having anoptical anisotropy in the range of about 0.08 to about 0.25 may beprepared by controlling the ratio of the component compounds or bymixing with any other liquid crystal compound. The composition can beused as the composition having the nematic phase, and as the opticallyactive composition by adding the optically active compound.

The composition can be used for the AM device. The composition can alsobe used for a PM device. The composition can be used for an AM deviceand a PM device each having a mode such as PC, TN, STN, ECB, OCB, IPS,VA or PSA. Use for the AM device having the PSA mode is particularlypreferred. The devices may be of a reflective type, a transmissive typeor a transflective type. Use for the transmissive device is preferred.The composition can also be used for an amorphous silicon-TFT device ora polycrystal silicon-TFT device. The composition can also be used for anematic curvilinear aligned phase (NCAP) device prepared bymicroencapsulating the composition, and for a polymer dispersed (PD)device in which a three-dimensional network-polymer is formed in thecomposition.

The liquid crystal display device of the invention is characterized bycomprising two substrates having an electrode layer on at least one ofthe substrates, and arranging between the two substrates the liquidcrystal composition of the invention or a liquid crystal compositioncontaining a compound formed by polymerization of the compound of theinvention. For example, the liquid crystal display device comprises twoglass substrates referred to as an array substrate and a color filtersubstrate, and a thin film transistor (TFT), pixels, a coloring layerand so forth are formed on each of the glass substrates. Aluminosilicateglass or aluminoborosilicate glass is used for each of the glasssubstrates, for example. For the electrode layer, Indium-Tin Oxide andIndium-Zinc Oxide are generally used.

EXAMPLES

In order to evaluate characteristics of a composition and a compound tobe contained in the composition, the composition and the compound weremade a measurement object. When the measurement object was thecomposition, the measurement object was measured as a sample as was, andvalues obtained were described. When the measurement object was thecompound, a sample for measurement was prepared by mixing the compound(15% by weight) into mother liquid crystals (85% by weight). Values ofcharacteristics of the compound were calculated using values obtained bymeasurement, according to an extrapolation method: (extrapolatedvalue)={(measured value of a sample for measurement)−0.85×(measuredvalue of mother liquid crystals)}/0.15. When a smectic phase (orcrystals) precipitated at the above ratio at 25° C., a ratio of thecompound to the mother liquid crystals was changed step by step in theorder of (10% by weight: 90% by weight), (5% by weight: 95% by weight)and (1% by weight: 99% by weight). Values of a maximum temperature,optical anisotropy, viscosity and dielectric anisotropy with regard tothe compound were determined according to the extrapolation method.

Components of the mother liquid crystals and ratio thereof were asdescribed below.

Characteristics were measured according to the methods described below.Most of the methods are applied as described in the Standard of JapanElectronics and Information Technology Industries Association, hereafterabbreviated as JEITA) (JEITA ED-2521B) discussed and established, or asmodified thereon.

Maximum Temperature of a Nematic Phase (NI; ° C.):

A sample was placed on a hot plate in a melting point apparatus equippedwith a polarizing microscope and was heated at a rate of 1° C. perminute. Temperature when a part of the sample began to change from anematic phase to an isotropic liquid was measured. A maximum temperaturerange of the nematic phase may be occasionally abbreviated as “maximumtemperature.”

Minimum Temperature of a Nematic Phase (T_(a); ° C.):

A sample having a nematic phase was put in glass vials and kept infreezers at temperatures of 0° C., −10° C., −20° C., −30° C. and −40° C.for 10 days, and then liquid crystal phases were observed. For example,when the sample maintained the nematic phase at −20° C. and changed tocrystals or a smectic phase at −30° C., T_(c) was expressed asT_(c)<−20° C. A minimum temperature of the nematic phase may beoccasionally abbreviated as “minimum temperature.”

Viscosity (Bulk Viscosity; η; Measured at 20° C.; mPa·s):

A cone-plate (E type) rotational viscometer was used for measurement.

Optical Anisotropy (Refractive Index Anisotropy; Δn; Measured at 25°C.):

Measurement was carried out by means of an Abbe refractometer with apolarizing plate mounted on an ocular, using light having a wavelengthof 589 nanometers. A surface of a main prism was rubbed in onedirection, and then a sample was added dropwise onto the main prism. Arefractive index (n∥) was measured when the direction of polarized lightwas parallel to the direction of rubbing. A refractive index (n⊥) wasmeasured when the direction of polarized light was perpendicular to thedirection of rubbing. A value of optical anisotropy was calculated froman equation: Δn=n∥−n⊥.

Dielectric Anisotropy (As; Measured at 25° C.):

A value of dielectric anisotropy was calculated from an equation:Δ∈=∈∥−∈⊥. A dielectric constant (∈∥ and ∈⊥) was measured as describedbelow.

(1) Measurement of dielectric constant (∈∥): An ethanol (20 mL) solutionof octadecyl triethoxysilane (0.16 mL) was applied to a well-cleanedglass substrate. After rotating the glass substrate with a spinner, theglass substrate was heated at 150° C. for 1 hour. A sample was put in aVA device in which a distance (cell gap) between two glass substrateswas 4 micrometers, and the device was sealed with an ultraviolet-curableadhesive. Sine waves (0.5 V, 1 kHz) were applied to the device, andafter 2 seconds, a dielectric constant (∈∥) in the major axis directionof liquid crystal molecules was measured.

(2) Measurement of dielectric constant (∈⊥): A polyimide solution wasapplied to a well-cleaned glass substrate. After calcining the glasssubstrate, rubbing treatment was applied to the alignment film obtained.A sample was put in a TN device in which a distance (cell gap) betweentwo glass substrates was 9 micrometers and a twist angle was 80 degrees.Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2seconds, a dielectric constant (∈⊥) in the minor axis direction of theliquid crystal molecules was measured.

Threshold Voltage (Vth; Measured at 25° C.; V):

An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. wasused for measurement. A light source was a halogen lamp. A sample wasput in a normally black mode VA device in which a distance (cell gap)between two glass substrates was 4 micrometers and a rubbing directionwas anti-parallel, and the device was sealed with an ultraviolet-curableadhesive. A voltage (60 Hz, rectangular waves) to be applied to thedevice was stepwise increased from 0 V to 20 V at an increment of 0.02V. On the occasion, the device was irradiated with light from adirection perpendicular to the device, and the amount of lighttransmitting the device was measured. A voltage-transmittance curve wasprepared, in which the maximum amount of light corresponds to 100%transmittance and the minimum amount of light corresponds to 0%transmittance. A threshold voltage is voltage at 10% transmittance.

Voltage Holding Ratio (VHR-1; Measured at 25° C.; %):

A TN device used for measurement had a polyimide alignment film, and adistance (cell gap) between two glass substrates was 5 micrometers. Asample was put in the device, and then the device was sealed with anultraviolet-curable adhesive. A pulse voltage (60 microseconds at 5 V)was applied to the TN device and the device was charged. A decayingvoltage was measured for 16.7 milliseconds with a high-speed voltmeter,and area A between a voltage curve and a horizontal axis in a unit cyclewas determined. Area B is an area without decay. A voltage holding ratiois a percentage of area A to area B.

Voltage Holding Ratio (VHR-2; Measured at 80° C.; %):

A TN device used for measurement had a polyimide alignment film, and adistance (cell gap) between two glass substrates was 5 micrometers. Asample was put in the device, and then the device was sealed with anultraviolet-curable adhesive. A pulse voltage (60 microseconds at 5 V)was applied to the TN device and the device was charged. A decayingvoltage was measured for 16.7 milliseconds with a high-speed voltmeter,and area A between a voltage curve and a horizontal axis in a unit cyclewas determined. Area B is an area without decay. A voltage holding ratiois a percentage of area A to area B.

Voltage Holding Ratio (VHR-3; Measured at 25° C.; %):

Stability to ultraviolet light was evaluated by measuring a voltageholding ratio after a device was irradiated with ultraviolet light. ATNdevice used for measurement had a polyimide alignment film and a cellgap was 5 micrometers. A sample was injected into the device, and thenthe device was irradiated with light for 20 minutes. A light source wasan ultra high-pressure mercury lamp USH-500D (made by Ushio, Inc.), anda distance between the device and the light source was 20 centimeters.In measuring VHR-3, a decaying voltage was measured for 16.7milliseconds. A composition having a large VHR-3 has a large stabilityto ultraviolet light. A value of VHR-3 is preferably 90% or more,further preferably, 95% or more.

Voltage Holding Ratio (VHR-4; Measured at 25° C.; %):

A TN device into which a sample was injected was heated in aconstant-temperature bath at 80° C. for 500 hours, and then stability toheat was evaluated by measuring a voltage holding ratio. In measuringVHR-4, a decaying voltage was measured for 16.7 milliseconds. Acomposition having a large VHR-4 has a large stability to heat.

Response Time (t; Measured at 25° C.; ms):

An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. wasused for measurement. A light source was a halogen lamp. A low-passfilter was set at 5 kHz. A sample was put in a normally black mode PVAdevice in which a distance (cell gap) between two glass substrates was3.2 micrometers and a rubbing direction was anti-parallel, and thedevice was sealed with an ultraviolet-curable adhesive. A voltage alittle over a threshold voltage was applied to the device for about 1minute, and then the device was irradiated with ultraviolet light of 25mW/cm² (EXECURE4000-D lamp made by HOYA CANDEO OPTRONICS CORPORATION)for about 8 minutes while a voltage of 5.6 V was applied to the device.Rectangular waves (60 Hz, 10 V, 0.5 second) were applied to the device.On the occasion, the device was irradiated with light from a directionperpendicular to the device, and the amount of light transmitted throughthe device was measured. The maximum amount of light corresponds to 100%transmittance, and the minimum amount of light corresponds to 0%transmittance. A response time is a period of time required for a changefrom 0% transmittance to 90% transmittance rise time (rise time;millisecond).

Specific Resistance (ρ; Measured at 25° C.; Ωcm):

Into a vessel equipped with electrodes, 1.0 milliliter of a sample wasinjected. A DC voltage (10 V) was applied to the vessel, and a DCcurrent after 10 seconds was measured. A specific resistance wascalculated from the following equation: (specificresistance)={(voltage)×(electric capacity of a vessel)}/{(DCcurrent)×(dielectric constant of vacuum)}.

Gas Chromatographic Analysis:

A GC-14B Gas Chromatograph made by Shimadzu Corporation was used formeasurement. A carrier gas was helium (2 mL per minute). A sampleinjector and a detector (FID) were set to 280° C. and 300° C.,respectively. A capillary column DB-1 (length 30 m, bore 0.32 mm, filmthickness 0.25 μm; dimethylpolysiloxane as a stationary liquid phase,non-polar) made by Agilent Technologies, Inc. was used for separation ofcomponent compounds. After the column was kept at 200° C. for 2 minutes,the column was heated to 280° C. at a rate of 5° C. per minute. A samplewas prepared in an acetone solution (0.1% by weight), and then 1microliter of the solution was injected into the sample injector. Arecorder was C-R5A Chromatopac made by Shimadzu Corporation or theequivalent thereof. The resulting gas chromatogram showed a retentiontime of a peak and a peak area corresponding to each of the componentcompounds.

As a solvent for diluting the sample, chloroform, hexane and so forthmay also be used. The following capillary columns may also be used forseparating component compounds: HP-1 (length 30 m, bore 0.32 mm, filmthickness 0.25 μm) made by Agilent Technologies, Inc., Rtx-1 (length 30m, bore 0.32 mm, film thickness 0.25 μm) made by Restek Corporation andBP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by SGEInternational Pty. Ltd. A capillary column CBP1-M50-025 (length 50 m,bore 0.25 mm, film thickness 0.25 μm) made by Shimadzu Corporation mayalso be used for the purpose of avoiding an overlap of peaks of thecompounds.

A ratio of liquid crystal compounds included in the composition may becalculated by the method as described below. The liquid crystalcompounds can be detected by means of a gas chromatograph. A ratio ofpeak areas in a gas chromatogram corresponds to a ratio (number ofmoles) of the liquid crystal compounds. When the capillary columnsdescribed above were used, a correction coefficient of each of theliquid crystal compounds may be regarded as 1 (one). Accordingly, aratio (% by weight) of the liquid crystal compounds was calculated fromthe ratio of the peak areas.

The invention will be explained in detail by way of Examples. Theinvention is not limited by the Examples described below. The compoundsin Comparative Examples and Examples were described using symbolsaccording to definitions in Table 3 below. In Table 3, a configurationof 1,4-cyclohexylene is trans. A parenthesized number next to asymbolized compound corresponds to the number of the compound. A symbol(−) means any other liquid crystal compound. A ratio (percentage) of theliquid crystal compounds is expressed in terms of weight percent (% byweight) based on the weight of the liquid crystal composition excludingthe first component. The liquid crystal composition further includes animpurity in addition thereto. Last, values of characteristics of thecomposition were summarized.

TABLE 3 Method for Description of Compounds using SymbolsR—(A₁)—Z₁—·····—Z_(n)—(A_(n))—R′ 1) Left-terminal Group R— SymbolsC_(n)H_(2n+1)— n- C_(n)H_(2n+1)O— nO— C_(m)H_(2m+1)OC_(n)H_(2n)— mOn-CH₂═CH— V— C_(n)H_(2n+1)—CH═CH— nV— CH₂═CH—C_(n)H_(2n)— Vn-C_(m)H_(2m+1)—CH═CH—C_(n)H_(2n)— mVn- CF₂═CH— VFF— CF₂═CH—C_(n)H_(2n)—VFFn- CH₂═CHCOO— AC— CH₂═C(CH₃)COO— MAC— 2) Right-terminal Group —R′Symbols —C_(n)H_(2n+1) -n —OC_(n)H_(2n+1) —On —CH═CH₂ —V—CH═CH—C_(n)H_(2n+1) —Vn —C_(n)H_(2n)—CH═CH₂ -nV —CH═CF₂ —VFF —COOCH₃—EMe —OCOCH═CH₂ —AC —OCOC(CH₃)═CH₂ —MAC 3) Bonding Group —Z_(n)— Symbols—C₂H₄— 2 —COO— E —CH═CH— V —C≡C— T —CF₂O— X —CH₂O— 1O —SiH₂— Si 4) RingStructure —An- Symbols

H

Dh

B

B(F)

B(2F)

B(2F,5F)

B(2F,3F)

B(2F,3F,6Me)

B(2F,3CL)

Np

Np(3F,4F,5F)

Cro(7F,8F) 5) Examples of Description Example 1 3-HB(2F,3F)-O2

Example 2 3-HDhB(2F,3F)-O2

Comparative Example 1

The composition is a liquid crystal composition that does not contain afirst component of the invention. Components and characteristics of thecomposition are as described below.

3-H2B(2F,3F)-O2 (2-2-1) 15% 5-H2B(2F,3F)-O2 (2-2-1) 10% 3-HBB(2F,3F)-O2(2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 8% 5-HBB(2F,3F)-O2 (2-13-1) 5%3-HHB(2F,3CL)-O2 (2-16-1) 4% 4-HHB(2F,3CL)-O2 (2-16-1) 3%3-HBB(2F,3CL)-O2 (2-17-1) 4% 2-HH-3 (3-1-1) 25% 3-HH-4 (3-1-1) 10%3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%

NI=77.5° C.; Tc≦−20° C.; Δn=0.089; Δ∈=−2.9; Vth=2.21 V; τ=7.5 ms;VHR-1=99.1%; VHR-2=97.9%.

Example 1

3-H2B(2F,3F)-O2 (2-2-1) 15% 5-H2B(2F,3F)-O2 (2-2-1) 10% 3-HBB(2F,3F)-O2(2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 8% 5-HBB(2F,3F)-O2 (2-13-1) 5%3-HHB(2F,3CL)-O2 (2-16-1) 4% 4-HHB(2F,3CL)-O2 (2-16-1) 3%3-HBB(2F,3CL)-O2 (2-17-1) 4% 2-HH-3 (3-1-1) 25% 3-HH-4 (3-1-1) 10%3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%

To 100 parts by weight of the composition, 0.15 part by weight ofcompound (1-1-1) as described below:

and 0.15 part of weight of compound (1-1-1) as described below:

were added.

NI=77.3° C.; Tc≦−20° C.; Δn=0.090; Δ∈=−3.0; Vth=2.20 V; τ=5.4 ms;VHR-1=99.1%; VHR-2=97.9%.

Example 2

3-HB(2F,3F)-O2 (2-1-1) 10% 3-H2B(2F,3F)-O2 (2-2-1) 13% 5-H2B(2F,3F)-O2(2-2-1) 13% 3-HHB(2F,3F)-O2 (2-6-1) 10% 5-HHB(2F,3F)-O2 (2-6-1) 8%2-BB(2F,3F)B-3 (2-9-1) 7% 2-HH-3 (3-1-1) 13% 3-HH-O1 (3-1) 5% VFF-HH-3(3-1) 5% 3-HHB-3 (3-5-1) 3% 3-HBB-2 (3-6-1) 6% 5-HBB(F)B-2 (3-13-1) 7%

To 100 parts by weight of the composition, 0.15 part by weight ofcompound (1-1-1) as described below:

and 0.15 part of weight of compound (1-1-1) as described below:

were added.

NI=75.3° C.; Tc≦−20° C.; Δn=0.105; Δ∈=−2.8; Vth=2.21 V; τ=3.8 ms;VHR-1=99.2%; VHR-2=98.3%.

Example 3

3-HB(2F,3F)-O2 (2-1-1) 12% 3-HB(2F,3F)-O4 (2-1-1) 12% 2-HDhB(2F,3F)-O2(2-11-1) 10% 3-HBB(2F,3F)-O2 (2-13-1) 6% 5-HBB(2F,3F)-O2 (2-13-1) 5%2-HH-3 (3-1-1) 15% 1V-HH-3 (3-1-1) 8% 3-HB-O2 (3-2) 8% V2-BB-1 (3-3-1)5% 3-HHEH-3 (3-4-1) 3% V2-HHB-1 (3-5-1) 6% 5-HBB(F)B-2 (3-13-1) 5%5-HBB(F)B-3 (3-13-1) 5%

To 100 parts by weight of the composition, 0.2 part by weight ofcompound (1-1-1) as described below:

and 0.2 part by weight of compound (1-1-1) as described below:

were added.

NI=78.4° C.; Tc≦−20° C.; Δn=0.106; Δ∈=−2.8; Vth=2.23 V; τ=4.0 ms;VHR-1=99.3%; VHR-2=98.3%.

Example 4

V-HB(2F,3F)-O2 (2-1-1) 10% V-HB(2F,3F)-O4 (2-1-1) 10%2O-B(2F,3F)B(2F,3F)-O6 (2-5) 3% 3-HHB(2F,3F)-O2 (2-6-1) 10%3-HBB(2F,3CL)-O2 (2-17-1) 8% 3-H1OCro(7F,8F)-5 (2-18-1) 3% 3-HH-4(3-1-1) 8% V-HH-3 (3-1-1) 30% 2-BB(F)B-3 (3-8-1) 5% 3-HHEBH-3 (3-9-1) 4%3-HB(F)HH-5 (3-10-1) 4% 5-HBB(F)B-3 (3-13-1) 5%

To 100 parts by weight of the composition, 0.3 part by weight ofcompound (1-1-1) as described below.

was added.

NI=76.4° C.; Tc≦−20° C.; Δn=0.095; Δ∈=−2.4; Vth=2.32 V; τ=4.2 ms;VHR-1=99.1%; VHR-2=98.0%.

Example 5

3-HB(2F,3F)-O2 (2-1-1) 10% 3-HB(2F,3F)-O4 (2-1-1) 9% 3-HHB(2F,3F)-O2(2-6-1) 8% 5-HHB(2F,3F)-O2 (2-6-1) 8% 2-BB(2F,3F)B-4 (2-9-1) 6%3-HEB(2F,3F)B(2F,3F)-O2 (2-15-1) 5% 3-HHB(2F,3CL)-O2 (2-16-1) 3%3-H1O-B(2F,3F,6Me)-O2 (2) 3% 3-HH1OB(2F,3F,6Me)-O2 (2) 6% 2-HH-3 (3-1-1)16% 7-HB-1 (3-2-1) 5% 1V2-BB-1 (3-3-1) 4% V-HHB-1 (3-5-1) 10%1-BB(F)B-2V (3-8-1) 4% 3-HB(F)BH-3 (3-12-1) 3%

To 100 parts by weight of the composition, 0.2 part by weight ofcompound (1-1-1) as described below:

and 0.2 part by weight of compound (1-1-1) as described below:

were added.

NI=82.0° C.; Tc≦−20° C.; Δn=0.110; Δ∈=−2.7; Vth=2.34 V; τ=5.0 ms;VHR-1=99.1%; VHR-2=98.0%.

Example 6

V-HB(2F,3F)-O2 (2-1-1) 15% 2-H1OB(2F,3F)-O2 (2-3-1) 10% 3-HH2B(2F,3F)-O2(2-7-1) 10% 5-HH2B(2F,3F)-O2 (2-7-1) 6% 3-DhHB(2F,3F)-O2 (2-10-1) 5%3-HDhB(2F,3F)-O2 (2-11-1) 5% 3-dhBB(2F,3F)-O2 (2-14-1) 5% 3-HH-4 (3-1-1)10% V-HH-4 (3-1-1) 9% 5-HB-O2 (3-2) 6% 1V-HBB-2 (3-6-1) 5% 2-BB(F)B-5(3-8-1) 8% 5-HBBH-3 (3-11-1) 3% 3-HH1OH-3 (3) 3%

To 100 parts by weight of the composition, 0.3 part by weight ofcompound (1-1-1) as described below:

and 0.2 part by weight of compound (1-1-1) as described below:

were added.

NI=78.5° C.; Tc≦−20° C.; Δn=0.104; Δ∈=−3.5; Vth=2.12 V; τ=5.1 ms;VHR-1=99.2%; VHR-2=98.3%.

Example 7

3-H2B(2F,3F)-O2 (2-2-1) 20% 5-H2B(2F,3F)-O2 (2-2-1) 10% 3-HHB(2F,3F)-O2(2-6-1) 8% 5-HHB(2F,3F)-O2 (2-6-1) 4% 3-HDhB(2F,3F)-O2 (2-11-1) 5%3-HBB(2F,3F)-O2 (2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 6% 5-HBB(2F,3F)-O2(2-13-1) 4% 2-HH-3 (3-1-1) 20% 3-HH-4 (3-1-1) 9% 3-HHB-1 (3-5-1) 4%

To 100 parts by weight of the composition, 0.2 part by weight ofcompound (1-1-1) as described below:

was added.

NI=77.4° C.; Tc≦−20° C.; Δn=0.090; Δ∈=−3.6; Vth=1.86 V; τ=5.6 ms;VHR-1=99.1%; VHR-2=98.2%.

Example 8

3-H2B(2F,3F)-O2 (2-2-1) 20% 5-H2B(2F,3F)-O2 (2-2-1) 10% 3-HHB(2F,3F)-O2(2-6-1) 8% 5-HHB(2F,3F)-O2 (2-6-1) 4% 3-HDhB(2F,3F)-O2 (2-11-1) 5%3-HBB(2F,3F)-O2 (2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 6% 5-HBB(2F,3F)-O2(2-13-1) 4% 2-HH-3 (3-1-1) 20% 3-HH-4 (3-1-1) 9% 3-HHB-1 (3-5-1) 4%

To 100 parts by weight of the composition, 0.1 part by weight ofcompound (1-1-1) as described below:

and 0.1 part by weight of compound (1-1-1) as described below:

were added.

NI=77.5° C.; Tc≦−20° C.; Δn=0.090; Δ∈=−3.6; Vth=1.86 V; τ=5.7 ms;VHR-1=99.0%; VHR-2=98.2%.

Example 9

3-HB(2F,3F)-O2 (2-1-1) 8% 1V2-HB(2F,3F)-O2 (2-1-1) 6% 3-H2B(2F,3F)-O2(2-2-1) 12% 1V2-H2B(2F,3F)-O2 (2-2-1) 5% 1V2-HH2B(2F,3F)-O2 (2-7-1) 4%3-HH1OB(2F,3F)-O2 (2-8-1) 12% 3-HDhB(2F,3F)-O2 (2-11-1) 3%3-DhH1OB(2F,3F)-O2 (2-12-1) 3% V-DhH1OB(2F,3F)-O2 (2-12-1) 3%V-HBB(2F,3F)-O2 (2-13-1) 4% 3-HH-5 (3-1-1) 3% V-HH-5 (3-1-1) 13% V2-HB-1(3-2-1) 5% 3-HHB-O1 (3-5) 4% 5-B(F)BB-2 (3-7-1) 5% V2-BB(F)B-1 (3-8-1)4% 3-HHEBH-3 (3-9-1) 3% 1O1-HBBH-4 (—) 3%

To 100 parts by weight of the composition, 0.3 part by weight ofcompound (1-1-1) as described below:

and 0.3 part by weight of compound (1-1-1) as described below:

were added.

NI=86.0° C.; Tc≦−20° C.; Δn=0.106; Δ∈=−3.9; Vth=1.87 V; τ=5.8 ms;VHR-1=99.2%; VHR-2=98.3%.

Example 10

3-H2B(2F,3F)-O2 (2-2-1) 15% 5-H2B(2F,3F)-O2 (2-2-1) 20% 3-HHB(2F,3F)-O2(2-6-1) 5% 3-HDhB(2F,3F)-O2 (2-11-1) 5% 3-HBB(2F,3F)-O2 (2-13-1) 10%5-HBB(2F,3F)-O2 (2-13-1) 5% 3-HH1OCro(7F,8F)-5 (2-19-1) 4% 2-HH-3(3-1-1) 20% 3-HH-4 (3-1-1) 4% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%3-HHEBH-3 (3-9-1) 3% 3-HHEBH-4 (3-9-1) 3%

To 100 parts by weight of the composition, 0.15 part by weight ofcompound (1-1-1) as described below:

and 0.15 part by weight of compound (1-1-1) as described below:

were added.

NI=82.0° C.; Tc≦−20° C.; Δn=0.090; Δ∈=−3.7; Vth=1.82 V; τ=5.3 ms;VHR-1=99.2%; VHR-2=98.1%.

Example 11

3-H2B(2F,3F)-O2 (2-2-1) 15% 5-H2B(2F,3F)-O2 (2-2-1) 20% 3-HHB(2F,3F)-O2(2-6-1) 5% 3-HDhB(2F,3F)-O2 (2-11-1) 5% 3-HBB(2F,3F)-O2 (2-13-1) 10%5-HBB(2F,3F)-O2 (2-13-1) 5% 3-HH1OCro(7F,8F)-5 (2-19-1) 4% 2-HH-3(3-1-1) 20% 3-HH-4 (3-1-1) 4% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%3-HHEBH-3 (3-9-1) 3% 3-HHEBH-4 (3-9-1) 3%

To 100 parts by weight of the composition, 0.3 part by weight ofcompound (1-1-1) as described below:

was added.

NI=82.1° C.; Tc≦−20° C.; Δn=0.089; Δ∈=−3.6; Vth=1.83 V; τ=5.2 ms;VHR-1=99.1%; VHR-2=98.1%.

Example 12

V-HB(2F,3F)-O2 (2-1-1) 13% V-HB(2F, 3F)-O4 (2-1-1) 13% 3-HBB(2F,3F)-O2(2-13-1) 10% 5-HBB(2F,3F)-O2 (2-13-1) 10% 3-HHB(2F,3CL)-O2 (2-16-1) 3%5-HHB(2F,3CL)-O2 (2-16-1) 3% 2-HH-3 (3-1-1) 25% 3-HB-O2 (3-2) 3% 3-HHB-1(3-5-1) 4% 3-HHB-3 (3-5-1) 4% 3-B(F)BB-2 (3-7-1) 6% 3-HHEBH-3 (3-9-1) 3%3-HHEBH-4 (3-9-1) 3%

To 100 parts by weight of the composition, 0.4 part by weight ofcompound (1-1-1) as described below:

was added.

NI=78.9° C.; Tc≦−20° C.; Δn=0.100; Δ∈=−3.0; Vth=2.23 V; τ=4.7 ms;VHR-1=99.1%; VHR-2=98.0%.

Example 13

3-H2B(2F,3F)-O2 (2-2-1) 12% 5-H2B(2F,3F)-O2 (2-2-1) 12% 3-HDhB(2F,3F)-O2(2-11-1) 6% 3-HBB(2F,3F)-O2 (2-13-1) 11% 5-HBB(2F,3F)-O2 (2-13-1) 11%3-HH1OCro(7F,8F)-5 (2-19-1) 8% 2-HH-3 (3-1-1) 25% 3-HH-4 (3-1-1) 5%3-HHB-1 (3-5-1) 4% 3-HHB-3 (3-5-1) 3% 3-HHEBH-3 (3-9-1) 3%

To 100 parts by weight of the composition, 0.15 part by weight ofcompound (1-1-1) as described below:

and 0.15 part by weight of compound (1-1-1) as described below:

were added.

NI=84.5° C.; Tc≦−20° C.; Δn=0.092; Δ∈=−3.7; Vth=2.22 V; τ=5.0 ms;VHR-1=99.2%; VHR-2=98.3%.

Example 14

3-BB(2F,3F)-O2 (2-4-1) 12% 2-HH1OB(2F,3F)-O2 (2-8-1) 10%3-HH1OB(2F,3F)-O2 (2-8-1) 20% 3-HDhB(2F,3F)-O2 (2-11-1) 5% 2-HH-3(3-1-1) 21% 3-HH-4 (3-1-1) 10% 3-HB-O2 (3-2) 10% 1-BB-3 (3-3-1) 3%3-HHB-1 (3-5-1) 3% 5-B(F)BB-2 (3-7-1) 6%

To 100 parts by weight of the composition, 0.15 part by weight ofcompound (1-1-1) as described below:

and 0.15 part by weight of compound (1-1-1) as described below:

were added.

NI=75.0° C.; Tc≦−20° C.; Δn=0.097; Δ∈=−3.2; Vth=2.19 V; τ=5.5 ms;VHR-1=99.4%; VHR-2=98.1%.

Example 15

3-BB(2F,3F)-O2 (2-4-1) 12% 2-HH1OB(2F,3F)-O2 (2-8-1) 10%3-HH1OB(2F,3F)-O2 (2-8-1) 20% 3-HDhB(2F,3F)-O2 (2-11-1) 5% 2-HH-3(3-1-1) 21% 3-HH-4 (3-1-1) 10% 3-HB-O2 (3-2) 10% 1-BB-3 (3-3-1) 3%3-HHB-1 (3-5-1) 3% 5-B(F)BB-2 (3-7-1) 6%

To 100 parts by weight of the composition, 0.3 part by weight ofcompound (1-1-1) as described below:

was added.

NI=75.1° C.; Tc≦−20° C.; Δn=0.098; Δ∈=−3.3; Vth=2.21 V; τ=5.6 ms;VHR-1=99.3%; VHR-2=97.9%.

Example 16

3-BB(2F,3F)-O2 (2-4-1) 12% 2-HH1OB(2F,3F)-O2 (2-8-1) 10%3-HH1OB(2F,3F)-O2 (2-8-1) 20% 3-HDhB(2F,3F)-O2 (2-11-1) 5% 2-HH-3(3-1-1) 21% 3-HH-4 (3-1-1) 10% 3-HB-O2 (3-2) 10% 1-BB-3 (3-3-1) 3%3-HHB-1 (3-5-1) 3% 5-B(F)BB-2 (3-7-1) 6%

To 100 parts by weight of the composition, 0.1 part by weight ofcompound (1-2-1) as described below:

and 0.1 part by weight of compound (1-2-1) as described below:

were added.

NI=74.9° C.; Tc≦−20° C.; Δn=0.097; Δ∈=−3.2; Vth=2.24 V; τ=6.3 ms;VHR-1=99.2%; VHR-2=97.9%.

The compositions according to Example 1 to Example 16 have a shorterresponse time in comparison with the composition according toComparative Example 1.

INDUSTRIAL APPLICABILITY

The invention concerns a liquid crystal composition satisfying at leastone of characteristics such as a high maximum temperature of a nematicphase, a low minimum temperature of the nematic phase, a smallviscosity, a suitable optical anisotropy, a large negative dielectricanisotropy, a large specific resistance, a high stability to ultravioletlight and a high stability to heat, or a liquid crystal compositionhaving a suitable balance regarding at least two of the characteristics.A liquid crystal display device including such a composition is appliedto constitute an AM device having a short response time, a large voltageholding ratio, a large contrast ratio, a long service life and so forth,and thus can be used for a liquid crystal projector, a liquid crystaltelevision and so forth.

1. A liquid crystal composition containing at least one compoundselected from the group of compounds represented by formula (1) as afirst component and at least one compound selected from the group ofcompounds represented by formula (2) as a second component:

wherein R¹, R², R³ and R⁴ are independently hydrogen, hydroxy, alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkenyl having 2 to 12 carbons in which arbitraryhydrogen is replaced by fluorine, or a polymerizable group, and at leastone of R¹, R², R³ and R⁴ is a polymerizable group; R⁵ and R⁶ areindependently alkyl having 1 to 12 carbons, alkoxy having 1 to 12carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12carbons in which arbitrary hydrogen is replaced by fluorine; ring A andring C are independently 1,4-cyclohexylene, 1,4-phenylene in whicharbitrary hydrogen may be replaced by fluorine or chlorine, ortetrahydropyran-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹,Z², Z³ and Z⁴ are independently a single bond, oxygen, carbonyloxy,alkylene having 1 to 12 carbons or alkylene having 1 to 12 carbons inwhich arbitrary —CH₂— is replaced by —O—; Z⁵ and Z⁶ are independently asingle bond, ethylene, methyleneoxy or carbonyloxy; m is 1, 2 or 3; andn is 0 or 1, and a sum of m and n is 3 or less.
 2. The liquid crystalcomposition according to claim 1, wherein the first component is atleast one compound selected from the group of compounds represented byformula (1), and R¹, R², R³ and R⁴ are independently hydrogen, hydroxy,alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyl having 2 to 12 carbons in whicharbitrary hydrogen is replaced by fluorine, acrylate, methacrylate,vinyloxy, propenyl ether, oxirane, oxetane or vinyl ketone, and at leastone of R¹, R², R³ and R⁴ is acrylate, methacrylate, vinyloxy, propenylether, oxirane, oxetane or vinyl ketone.
 3. The liquid crystalcomposition according to claim 1, wherein the first component is atleast one compound selected from the group of compounds represented byformula (I-1) to formula (I-2):

wherein R² is hydrogen, hydroxy, alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2to 12 carbons in which arbitrary hydrogen is replaced by fluorine, or apolymerizable group.
 4. The liquid crystal composition according toclaim 1, wherein the second component is at least one compound selectedfrom the group of compounds represented by formula (2-1) to formula(2-19):

wherein R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine. 5-8. (canceled)
 9. The liquid crystal composition according toclaim 1, wherein a ratio of the first component is in the range of 0.05part by weight to 10 parts by weight based on 100 parts by weight of theliquid crystal composition excluding the first component, and a ratio ofthe second component is in the range of 10% by weight to 90% by weightbased on the weight of the liquid crystal composition excluding thefirst component.
 10. The liquid crystal composition according to claim1, further containing at least one compound selected from the group ofcompounds represented by formula (3) as a third component:

wherein R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine; ring D and ring E are independently 1,4-cyclohexylene,1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or2,5-difluoro-1,4-phenylene; Z⁷ is independently a single bond, ethylene,methyleneoxy or carbonyloxy; and p is 1, 2 or
 3. 11. The liquid crystalcomposition according to claim 10, wherein the third component is atleast one compound selected from the group of compounds represented byformula (3-1) to formula (3-13):

wherein R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenylhaving 2 to 12 carbons in which arbitrary hydrogen is replaced byfluorine. 12-15. (canceled)
 16. The liquid crystal composition accordingto claim 10, wherein a ratio of the third component is in the range of10% by weight to 90% by weight based on the weight of the liquid crystalcomposition excluding the first component.
 17. The liquid crystalcomposition according to claim 1, further containing a polymerizationinitiator.
 18. The liquid crystal composition according to claim 1,further containing a polymerization inhibitor.
 19. The liquid crystalcomposition according to claim 1, wherein a maximum temperatures of anematic phase is 70° C. or higher, an optical anisotropy (25° C.) at awavelength of 589 nanometers is 0.08 or more, and a dielectricanisotropy (25° C.) at a frequency of 1 kHz is −2 or less.
 20. A liquidcrystal display device, constituted of two substrates having anelectrode layer on at least one of the substrates, wherein the liquidcrystal composition according to claim 1 is arranged between the twosubstrates.
 21. The liquid crystal display device according to claim 20,wherein an operating mode of the liquid crystal display device is a TNmode, a VA mode, an IPS mode or a PSA mode, and a driving mode of theliquid crystal display device is an active matrix mode.
 22. Use of theliquid crystal composition according to claim 1 in a liquid crystaldisplay device.